body{
    margin: 0;
    padding: 0;
    width: 100%;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}


.father{
    display: flex;
    width: 100vw;
    justify-content: space-between;
}


.son1{
    background-color: orange;
    min-height: 300px;
    flex: 1;
    padding: 10px;
}

.son2{
    background-color: skyblue;
    min-height: 300px;
    flex: 1;
    padding: 10px;
}






.levelA{
    background-color: aqua;
    padding: 20px;
    width: 500px;
}

.levelB{
    background-color: green;
    padding: 20px;
}

.levelC{
    background-color: orange;
    padding: 20px;
}



.btn{
    border: 1px solid #fff;
    margin: 5px;
    padding: 10px;
    background-color: rgb(8, 92, 238);
    color: #fff;
    transition: opacity 0.5s ease;
}

.btn:hover{
    opacity: 0.6;
    transition: opacity 0.5s ease;
}


.btn.active{
    background-color: rgb(3, 150, 0);
}